A monument marks the Kildeer Mountain area where US soldiers clashed with Native American in 1864, near Killdeer, N.D. The site was surveyed by a team of archeologists when a power company wanted to run new power lines through the area. Indian tribes feared the project could disturb the remains of native people who were killed there but archeologists hired by the utility found “nothing of consequence” along a 150-foot right of way.

TIOGA, N.D. — Drilling crews are eager to plunge their equipment into the ground. Road builders are ready to start highway projects, and construction workers need to dig.

But across the hyperactive oil fields of North Dakota, these and other groups have to wait for another team — archaeologists, who often must survey the land before a single spade of dirt can be turned.

The routine surveys have produced a rare jobs bonanza in American archaeology, a field in which many highly educated professionals hop from project to project around the world and still struggle to make a living. The positions also come with a constant tension: The archaeologists are trained to find evidence of the past, but the companies that pay them would prefer not to turn up anything that gets in the way of profits.

Without the oil boom, a lot of young archaeologists might “never get the experience,” said Tim Dodson, who endured a long job search before finding work overseas and later coming to North Dakota.

Archaeological surveys are intended to protect any historical treasures that might lie buried atop the region’s oil and natural gas deposits. Although not required on all oil projects, they are a mandate for most federal drilling permits.

The work involves inspecting a site for any artifacts or evidence of past human habitation and cataloging the effort. If significant discoveries emerge, most oil companies will change their plans to avoid the hassle of drilling in a sensitive area.

Long before the oil boom, previous archaeological digs uncovered a nearly complete duck-billed dinosaur fossil with skin, bones and tendons preserved in sandstone. Other excavations have focused on old trading posts, military forts and battlefields, according to the State Historical Society of North Dakota.

With more archaeologists working in the oil fields, the number of historic sites in North Dakota jumped from 846 in 2009 to nearly 2,260 in 2013, including forgotten settler cemeteries with graves marked in foreign languages, abandoned homesteader farms and stone circles put in place by American Indians thousands of years ago, according to the state’s Historic Preservation Office.

“A lot of that wouldn’t be happening without the boom,” said Richard Rothaus, an archaeologist who heads Trefoil Cultural and Environmental Heritage, a Minnesota-based firm that offers “cultural resource management,” an umbrella term for this kind of archaeological work.

While the oil boom is the engine behind the speedy growth, the archaeological work is not focused entirely on drilling sites. Much of it targets building projects designed to support the oil business, such as road, bridge and airport improvements.

Over the last decade, the number of firms authorized to do surveys in North Dakota rose from around 30 to 50, said Paul Picha, chief archaeologist at the historical society.

No one in the field keeps track of exact archaeology employment numbers, but the oil boom has almost certainly expanded the ranks of North Dakota archaeologists from as few as a few dozen to several hundred, if not more.

For instance, the Bismarck office of Metcalf Archaeological Consultants has roughly doubled in size every year for the past three years, according to Damita Engel, regional director of operations at the firm, which is based in Golden, Colorado.